Clip-on fan



FIG. 1 is a perspective view of a clip-on fan;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a right-side view thereof;

FIG. 5 is a left-side view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken lines illustrate portions of the clip-on fan that form no part of the claimed design. 

CLAIM The ornamental design for a clip-on fan, as shown and described. 